The present invention relates to a radio communication connection destination specifying method suitable for a radio communication system using a radio wave with weak directivity and, more specifically, to a radio communication connection destination specifying method which can easily specify a connection destination by using infrared radiation with strong directivity for radio communication between electronic information communication devices in a radio communication system.
Conventionally, communication connection between electronic information communication devices is generally done by a wire scheme. Recently, attempts have been extensively made to increase the usability using a radio scheme instead.
An example of a radio communication system using a radio wave that has already been put into practical use and proliferated is an IrDA (Infrared Data Association) system using infrared radiation with strong directivity for radio communication between electronic information communication devices. In the IrDA system, however, the light-emitting surface (transmitting surface) and light-receiving surface (receiving surface) of opposing electronic information communication devices must face each other without being shielded by any obstacle. For this reason, the use environment is limited to some extent.
A radio communication system capable of eliminating such limitation on use environment has also been proposed. For example, in a Bluetooth system using a radio wave with weak directivity, electronic information communication devices in an about 10-m radius area can be wirelessly connected using a radio wave. Such a radio communication system has no limitation on use environment, unlike the IrDA system, and is therefore expected to widely proliferate in the future.
Examples of general radio communication techniques between electronic information communication devices are disclosed in Japanese Patent Laid-Open No. 10-135910 “microcomputer mounted control panel and parking lot management system provided with control panel”, Japanese Patent Laid-Open No. 11-112643 “hand-free speech device”, and Japanese Patent Laid-Open No. 11-261738 “speaking system in portable telephone”.
To specify a connection destination in communication connection between electronic information communication devices, in the wire scheme, the electronic information communication devices are physically connected through a cable. In the IrDA scheme, the electronic information communication devices are physically made to face each other. To the contrary, the above-described Bluetooth system cannot be achieved using the above-described physical method. Since it is necessary to specify the connection destination by a logical identifier, the connection scheme becomes complex, and the connection destination cannot be easily specified.
FIGS. 6A to 6C show a procedure of specifying a connection destination in a conventional Bluetooth system.
In the conventional Bluetooth system, to specify a connection destination, at the initial phase, a portable telephone 3 serving as a main electronic information communication device transmits an inquiry request to wireless headsets 1 and 2 serving as peripheral electronic information communication devices, and each of the wireless headsets 1 and 2 returns an inquiry response (FIG. 6A). Next, at the intermediate phase, the user selects by key operation a desired connection destination (wireless headset 1) from the pieces of identification information of the wireless headsets 1 and 2 that have returned the inquiry responses and are displayed on a display screen 3a of the portable telephone 3 (FIG. 6B). At the final phase, a Bluetooth link is established for the wireless headset 1, i.e., the connection destination selected by the portable telephone 3 (FIG. 6C).
In the above-described Bluetooth system, a Bluetooth device address serving as an identifier is used as the device identification information of each of the wireless headsets 1 and 2. However, since the Bluetooth device address is a combination of a predetermined number of numbers and characters, the connection destination actually desired by the user can hardly be specified from the device list sent to the portable telephone 3.
That is, even when a method of displaying the identifiers (device identification information of the wireless headsets 1 and 2) on each electronic information communication device (portable telephone 3) is applied, the user must know in advance the identifier (device identification information of the wireless headset 1 or 2) of the electronic information communication device as a desired connection destination. The reason for this is the same as in a normal telephone call, i.e., the user cannot make a telephone call unless he/she knows the telephone number of the other party in advance.